ScalingStacks

Lemma 5. Suppose $(\mathcal{C},\otimes,I)$ is a semistrict monoidal 2-category. Then $(\mathcal{C},\otimes^{\rm op},I)$ is also a semistrict monoidal 2-category, where $\otimes^{\rm op}=S_{\mathcal{C},\mathcal{C}}\circ\otimes$.